Centering and driving means for tools.



S. H.' 00X. GENTERING AND DRIVING MEANS FOR TOOLS:

Patented Nov. 22, 1910.

UNITED %TATE% TATENT @FFIQE.

SAMUEL H.

COX, 0]? CLEVELAND, OHIO, ASSIGNOR '10 TIE-IE CLEVELAND TWIST DRILLCOMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

CENTERING AND DRIVING MEANS FOR TOOLS.

Specification of Letters Patent.

Patented Nov. 22, 1910..

To all whom it may concern:

Be it known that I, SAMUEL H. Cox, a citizen of the United States,residing at Cleveland, in the county of Cuyahoga and State of Ohio, haveinvented a certain new and useful Improvement in Centering and DrivingMeans for Tools, lowing is a full, clear, and exact description.

This invention relates to means for centering a tool in a drivingspindle and for forming a driving connection between the spindle andtool, being especially adapted for, use in connection with tools knownas high speed tools or such as are formed from expensive material.

The ordinary or commercial twist drill is usually cut or milled from asolid bar and is provided with a cone shaped shank adapted to fit a coneshaped spindle opening and at the end of the shank is provided with atang which is adapted to engage within asuitable opening at the inner orsmall end of the cone shaped opening whereby the driving connection isformed between the tool and spindle. In forming tools in this manner somuch material is wasted that high speed drills which are generallyformed from high priced steel are frequently made by forging or twistingapproximately rectangular bars, the shank of .the drill being oftenformed with opposite flat tapered sides and with rounded tapered edges.The smaller sizes of high speed drills formed in this manner aregenerally centered and held in the spindle openings by means of socketsor bushings quite similar in external shape to the shank of an ordinarycommercial drill, this socket having an opening shaped to fit the shankof the drill and being conical or tapered on the exterior to fit thespindle opening and also having at its inner or small end a tang-likeextension which engages in the narrow opening at the inner or small endof the cone shaped spindle opening so as to form the driving connectionbetween the spindle and the socket and drill. This means for centeringthe drill and for forming the driving connection between the drill andspindle is unsuitable for larger sizes of drills, say from two to threeinches in diameter, for the reason that the shank of such a drill ifmade of the proper size to withstand torsional stresses is too large topermit the use of the cone shaped socket or bushing between the shankand spindle, especially as of which the folfew machines have a spindleopening larger than what is known as No. 5 standard taper. Thereforesome means for centering or centering and driving large drills otherthan the above mentioned sockets or bushings employed with the smallersizes, becomes necessary.

similar in shape to the shanks of the smaller drills,-that is, with twoopposite fiat sides and with rounded tapered edges, but for the largerdrills, the edges are turned to the exact standard taper of the machinespindle, the thickness at the smaller end being the same as thethickness of the tang on a milled drill. It is obvious that when theshank is so formed it will fit the corresponding standard taperedspindle opening and that the driving connection will be provided thesame as with the smaller high speed drills or with the milled drills,but at the base or large end of the spindle opening there will be anopen space on each side of the fiat shank.

One of the objects of the invention is to provide a means for fillingthese open spaces and to eiiectively center the fiat shank and preventit from moving laterally in the spindle opening and from battering orinjuring its inner wall.

A further object which is attained in the preferred form of myinvention, is to provide a powerful auxiliary driving device tosupplement the driving which is obtained at the inner end of the shankby reason of the driving connection between this end and the slot in thespindle in which it engages.

In carrying out my invention, I provide a device which is employed atthe end of the spindle and which when utilized in connection with drillshaving shanks formed in the manner above stated, that is with oppositefiat sides and with edges rounded and tapered to fit the spindleopening, is in the form of a collar having an opening through which theshank extends and which is shaped substantially to fit the shank, andhaving also a pair of lugs which extend inwardly between the shank andthe spindle, to fill the openings, previously referred to, between thefiat sides of the shank and the inner rounded wall of the spindleopening, said lugs having inner flat faces which are engaged by theopposite fiat sides of the shank and having outer surfaces rounded andtapered to fit the conical wall of the I make the shank on the largerdrills uted that spindle opening. This device holds and centers theshank in a very effective manner. In the preferred form of my invention,this device is utilized also as an auxiliary driv-' ing means betweenthe tool and spindle and for this purpose the collar and spindle areprovided with interlocking parts which may be formed by providing amortise slot at the end of the spindle and by milling off portions ofthe collar, leaving projections which engage in the mortise slot. Withthis arrangement, the shank is driven both at its inner end and at itsouter end, and consequently is not only centered in the spindle opening,but the driving means is so distribthe shank can not be twisted.

My lnvention may be further briefly summarized as consisting in certainnovel details of construction and combinations and arrangements of partswhich will be described '111 the specification and set forth in theclaims.

For a better understanding of my invention, reference should be had tothe accompanying drawings wherein Figure l is a view showing a portionof the spindle in vertical section and showing a portion of the tool andcombined driving and centering device in elevation, a portion of thelatter being broken away; Fig. 2 is a snnilar view with the parts turnedninety substantially along the line 3-3 degrees Fig. 3 is a transversesectional view of Fig. 2, looking in the direction indicated by thearrow; Fig. 4 is a transverse sectional view substantially along theline 4; l of Fig. 1.

looking in the direction indicated by the arrow; and Fig. 5 is aperspective View of the centering and driving device.

Referring now to the figures of the drawing, 10 represents the drillspindle which is provided with a conical opening or socket 11, and atthe inner end of the conical opening with a narrow slot 12 which extendslaterally or transversely through the spindle so as to receive the tangof the tool and form a drift slot to permit the tool to be removed fromthe spindle.

13 represents the tool which is the spindle, which tool may be of ableform, such as a twist drill. is provided with a shank 1 1 havingopposite flat tapered sides 1 1 and having edges 14 which are curved orrounded concentrically with respect to the axis of the spindle and aretapered in accordance with the taper of the spindle opening 11 so as tofit or engage the wall of the same. The inner end of the shank, asappears particularly from Fig. 2, extends into the slot 12, so as toprovide the driving connection bet-ween the spindle and the inner end ofthe shank, as with the ordinary commercial twist drills. It is seentherefore that although the edges of the shank are so formed as to fittightly the wall driven by any suit- The tool is shaped to substantiallyfit the latter when Y the shank is the full spindle, tending otherwiseopen spaces between the flat tapered sides of the shank and the wall ofthe outer portion of the conical spindle opening. These lugs aretherefore provided with inner flat faces l6 which are tapered inwardlyin accordance with the taper of the sides 14. of the shank and which arepreferably flush with the sides of the opening 15 in the col lar 15 sothat said faces engage the sides 14 of the shank with a close fit. Thelugs are also provided with outer curved or rounded surfaces 16 whichform portions of the same conical surface and are tapered to fit thewall of the conical spindle opening.

In order that the device at the end of the spindle may, in addition tocentering the tool, form with the spindle an auxiliary driving means,the spindle and collar are provided with interlocking driving parts.Preferably, these interlocking parts are formed by providing a mortiseslot l0 on the end of the spindle and by cutting away portions of theinner part of the collar on opposite sides so as to form projections 15which engage in the mortise slot 10. In order that the centering anddriving device may be readily removed from the spindle, the projections15 are provided with slightly tapered slots 15 into which the end of asuitable removing tool may be inserted.

I do not desire to be confined to the exact details shown, but aim in myclaims to cover all modifications which do not involve a departure fromthe spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. In combination a spindle having a conical opening therein, a toolhaving a shank which extends into said opening and is provided withopposite substantially flat sides and with edges rounded and tapered tofit the conical wall of the spindle opening, and a device at the end ofthe spindle comprising a collar through which the shank eX' tends, andinwardly projecting lugs having inner faces which engage the oppositeflat sides of the shank, and outer rounded surfaces which engage theconical wall of the spindle opening.

.2. In combination, a spindle having a conical opening therein, a toolhaving :1 shank which extends into the opening and distance within theand having a pair of inwardly exlugs 16 which occupy or fill the isprovided with opposite flat tapered sides and edges rounded and taperedto fit the conical wall of the spindle opening, and a device at theouter end of the spindle comprising a collar through which the shankextends, and inwardly projecting lugs having inner fiat faces whichengage the flat tapered sides of the shank, and outer surfaces whichengage and are rounded and tapered to fit the wall of the spindle openmI In combination, a spindle having a conical opening therein, a toolhaving a shank which projects into said opening and is provided withopposite flat tapered sides and with edges rounded and tapered to fitthe conical walls of the spindle opening, and centering and drivingmeans for the outer portion of the shank comprising collar at the end ofthe spindle provided with an opening shaped to substantially fit theshank and with inwardly projecting lugs which engage the conical wall ofthe spindle opening and engage the opposite flat tapered sides of theshank, said collar and spindle having interlocking portions.

4:. In combination, a spindle having a conical opening therein, a toolhaving a shank which has a driving connection with the spindle at theinner end of the conical opening, and is provided with tapered flatopposite sides and with edges rounded and tapered to fit the conicalwall of the spindle opening, and means for centering the tool in thespindle opening and for forming an aux: iliary driving connectionbetween the spindle and tool comprising a collar having an openingthrough which the shank extends,

and inwardly projecting lugs having inner tapered faces which engage theopposite fiat tapered faces of the shank, and outer surfaces which fitthe conical wall of the spindle opening, the spindle and collar havinginterlocking portions formed by a slot in one of the members, and aprojection on the other member engaging in the slot.

5. As an article of manufacture, means for centering a tool in a spindleopening comprising a collar provided with a substantially rectangular oening extending there through and provi ed on one side with a pair oflugs which are spaced apart and are provided with inner substantiallyfiat faces, and with outer surfaces rounded concentrically with respectto each other.

6. As an article of manufacture, means for centering a tool in a spindleopening and for forming a driving connection between the tool andspindle, comprising a collar having a substantially rectangular openingextending therethrough and provided on one side with a projectionadapted to interlock with the end of the spindle and with a pair of lugsadapted to extend into the spindle opening, said lugs being providedwith oppositely disposed inner flat faces slightly tapered and flushwith the sides of the opening of the collar, and with outer sidesurfaces rounded concentrically with respect to each other and formingportions of a conical surface.

In testimony whereof, I hereunto affix my signature in the presence oftwo witnesses.

SAMUEL H. COX.

Witnesses:

H. R. SULLIVAN, A. J. HUDSON.

